This invention relates to a process for producing at least one monofilament from a thermoplastic polymer material. The present invention further relates to a use for the monofilament.
Monofilaments are used for example for producing artificial turf. Further uses include for example artificial hair for wigs and also bristles for soft or stiff brushes.
Artificial turf is used for example in outdoor areas of hotel establishments or on sports fields. Depending on the kind of sport practiced on the sports fields it is particularly the bend recovery or else the sliding properties of the artificial turf fibers that are important. Artificial turf fibers currently utilize polyolefins which have good sliding properties but only poor bend recovery. Alternatively, it is known to use polyamides for making artificial turf which have good bend recovery. Polyamides are used for example for artificial turfs of field hockey pitches. Polyamides, however, have the disadvantage of poor sliding properties. To ensure acceptable coefficient of friction values, pitches or fields equipped with artificial turf composed of polyamide fibers have to be regularly watered.
To improve the properties of artificial turf surfaces, research is currently focusing particularly on different fiber geometries; the combination of different fibers in tufting; or the use of coextruded multipolymer fibers. However, these solutions only ever address partial aspects of the principal requirements, which are low friction, good bend recovery and low cost.
Artificial turf that utilizes polyolefins still does not have the ideal bend recovery despite optimized geometry for the synthetic turf monofils. By contrast, polyamides exhibit high coefficient of friction values which can cause player injury when the field, pitch or court has not been sufficiently and uniformly watered. Similarly, the use of different fibers for making artificial turf does not lead to the desired performance profile since bend recovery and friction characteristics are primarily dominated by the longer fiber.
The use of coextruded fibers for producing artificial turf is economically unattractive at present.